The fortunes of miners such as BHP and Rio Tinto has been boosted by an increased demand from emerging economies such as China and India in recent years.

However, growth in these economies has been slowing down after policymakers tightened monetary policies in an attempt to control rising consumer prices and prevent the formation of asset bubbles.

Data released on Tuesday showed that China, the world's second-largest economy and one of the biggest consumers of iron-ore, grew at the slowest pace in almost two years in 2011.

Its gross domestic product grew by 9.2% last year, down from 10.4% in 2010.

However, analysts said that despite the slowdown fears, mining companies have been optimistic about future demand.

"These companies are pretty gung ho on iron ore and I don't think they would be out there crazily expanding if they thought there was a chance the volumes might not find a home," said Mark Taylor of Morningstar.

Some analysts said that a slowdown in the Chinese economy may actually result in increased spending by the Chinese authorities on infrastructure in an attempt to sustain growth, a move that was likely to boost demand for minerals.

Record year

On Tuesday, Rio Tinto said iron ore production had risen to a record during the October to December period, recovering from disruptions from severe weather earlier in the year.

Output came in at 51.2 million metric tonnes in the three months to the end of December, compared with 50.1 million a year earlier.

The mining giant attributed the growth to expansion at mines and ports in the Pilbara region of Australia.

"This was another record-breaking year in the Pilbara with both quarterly and full-year iron ore production and shipments beating previous achievements as our expansion programme continues apace," said Rio Tinto chief executive Tom Albanese.